This application claims the priority of German Application No. DE 100 05 245.2, filed in Germany on Feb. 5, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a tunnel region of a floor structure of a bodyshell of a motor vehicle with a transverse bridge for reinforcing the tunnel region, which is held by brackets fixed on side walls of the tunnel region and to a transverse bridge for this purpose. The side walls are designed to extend obliquely outwards in an adjoining supporting region below the brackets.
It is well-known in the case of passenger cars to close off the downwardly open tunnel profile of a tunnel region of a floor structure of a bodyshell of the passenger car at the level of the passenger compartment with a flat transverse bridge in order to reinforce the floor structure, a corresponding part of an exhaust system being positioned on the underside of this transverse bridge. The transverse bridge is screwed to two brackets, which are fixed on obliquely extending side walls of the tunnel region by welding. A gear-change mechanism is furthermore accommodated on the tunnel region, above the transverse bridge, this mechanism being positioned at a suitable point on the tunnel profile.
Another known practice from German Patent Documents DE 24 35 545 B2 or DE 197 02 669 A1 for holding the vehicle gearbox in the front area of the passenger compartment is to assign to the tunnel region a gearbox bridge, which carries the vehicle gearbox and bridges the tunnel profile of the tunnel region.
An object of the invention is to provide a tunnel region of the type stated at the outset which has a transverse bridge that can perform additional functions apart from that of transverse reinforcement.
This object is achieved, according to preferred embodiments of the invention, in that the side walls are aligned vertically, parallel to one another, in the region in which the brackets are attached, in that the brackets are fixed opposite one another on the side walls, at the same height relative to an upper side of the tunnel region, and that the transverse bridge is connected to the brackets at at least two fixing points, in particular in a removable manner.
The preferred embodiments according to the invention ensure that the transverse bridge is positioned below the upper side of the tunnel region at a distance which is accurate and uniform across its width. It is preferably aligned in an exactly horizontal manner. In the prior art, in contrast, the attachment of the brackets to the side walls of the tunnel region was subject to tolerances, making it impossible to achieve accurate predeterminable positioning of the transverse bridge relative to the upper side of the tunnel region. On the contrary, the position of the transverse bridge varied on different vehicles in a series depending on the respective tolerances of the floor structures of the tunnel region at the bodyshell stage.
The preferred embodiment according to the invention and the accurate, properly adjusted positioning of the transverse bridge relative to the upper side of the tunnel region makes it possible to confer additional functions on the transverse bridge. It is particularly advantageous here to involve the transverse bridge in accepting a gear-change mechanism. In contrast to the prior art, in which the corresponding gear-lever arrangement of the gear-change mechanism was provided on the upper side of the tunnel region, it is now possible to recess corresponding parts of the gear-change mechanism directly into the tunnel region and to use the transverse bridge to hold corresponding parts of the gear-change mechanism. The preferred embodiments according to the invention, which allow almost tolerance-free installation of the transverse bridge, create the conditions for such an additional function of the transverse bridge.
In a preferred embodiment of the invention, the transverse bridge is fixed on the brackets from below. In this case, particularly simple installation of the transverse bridge on the welded-in brackets can be achieved. This is advantageous particularly if the transverse bridge is connected removably to the brackets since, in this case, the transverse bridge can be removed again from below in a simple manner.
In another preferred embodiment of the invention, the transverse bridge has supporting extensions that extend obliquely downwards and outwards on opposite sides. These ensure the desired transverse supporting function and rigidity for raising the floor structure in a corresponding side impact. The transverse bridge and, in particular, its supporting extensions are preferably positioned in such a way at the level of floor members, each adjoining laterally at the outside, that force can be transmitted directly between the floor crossmembers and the transverse bridge, including the supporting extensions of the latter. The essential point here is that, in their obliquely outward- and downward-extending form, the supporting extensions are matched in such a way to the corresponding configuration of the side walls of the tunnel region at the level of these supporting extensions that the supporting extensions extend essentially parallel to these side wall portions and rest at least approximately directly on these side wall portions. This ensures that, in a corresponding side impact, the corresponding side wall of the tunnel region comes to rest at least virtually without deformation directly on the associated supporting extension of the transverse bridge, thus ensuring that the corresponding impact forces are directed into the transverse bridge and are transmitted into the opposite side wall of the tunnel region via the opposite supporting extension and directly onwards into the adjoining floor crossmember.
In another preferred embodiment of the invention, the transverse bridge has a downwardly open U-type profile. This ensures high rigidity combined with a relatively low weight of the transverse bridge.
In another preferred embodiment of the invention, the transverse bridge has a central part, to which the supporting extensions are joined as separate components. This makes the transverse bridge simpler to manufacture. It is particularly advantageous if the supporting extensions are connected to the central part by means of a cohesive joining method, in particular by laser welding. This results in a very accurate and high-quality connection between the supporting extensions and the central part.
In another preferred embodiment of the invention, the transverse bridge is provided with receptacles and/or fixing means for holding a gear-change mechanism. This allows corresponding parts of the gear-change mechanism to be attached to the transverse bridge in a particularly simple and reliable manner. It is advantageously even possible to preassemble the gear-change elements on the transverse bridge and to insert the preassembled unit into the tunnel region and connect it to the brackets.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.